Hitachi Consumer Electronics Co., Ltd.

Hitachi, Ltd.

Hitachi-lg Data Storage, Inc.

Junya Iizuka

Koichiro Nishimura

Yutaka Nagai

Takakiyo Yasukawa

Manabu Katsuki

In an optical information recording device and optical information recording method for angularly multiplexing and recording data on pages on the same recording region on a hologram disk, data on each page is sequentially generated by sequentially dividing input data in predetermined units, the pages to be recorded on the same recording region are divided into page groups so that pages to be recorded adjacently by the angular multiplexing may not belong to the same group, each page group is individually subjected to inter-page coding processing for computing an error-correcting code and adding the computed error-correcting code, and data on the pages subjected to the inter-page coding processing is angularly multiplexed and recorded on the hologram disk.

Optical information recording device and method

The pit arrays on an optical disc medium are made to wobble at a frequency which is higher than the band of frequencies that a tracking servo can follow and which is lower than the band of frequencies of the reproducing signal. A wobble detection signal according to the amount of wobble is obtained from the tracking error signal and used as a reference signal for frequency acquisition. Alternatively, the pit arrays on the medium are wobbled at a frequency which is within the band of frequencies that the tracking servo can follow and which is lower than the band of frequencies of the reproducing signal. In addition, a wobble detection signal corresponding to the amount of wobble is obtained either from the output signal from a compensator included in a tracking servo system or from a tracking drive signal and is used as a reference signal for frequency acquisition.

Optical disc medium, reproduction method thereof and reproduction apparatus

An optical disk apparatus is provided that has a signal processing circuit for equalizing a signal so as to achieve predetermined equalization, in which interference between codes is permitted, by means of an adaptive equalization circuit or the like, and for performing binarization by means of a maximum likelihood decoding circuit in which interference is performed as a rule, and thereby achieves stabilized signal reproduction in a narrow-band transmission. When evaluating the quality of the recorded signal through the use of the recording parameter learning and the reproduction system such as recorded signal verification, the optical disk recording apparatus is capable of highly precisely evaluating the quality of the recorded signal by fixing a circuit characteristic after suspending the optimization operation of the adaptive equalization circuit or the like for optimizing the characteristic by the reproduced signal. An optical disk recording method is also provided.

Optical disk recording apparatus

A need to effectively record data of various sizes on a large-capacity holographic memory capable of high-speed recording is achieved, for example, by curing a first part of the holographic recording which is able to be multiplex-recorded in one or more units of a predetermined volume, and by not recording/curing a second part which is not able to be multiplex-recorded in a predetermined volume at a timing when the first recording part is cured. Also the above need can be achieved by, another example, by adding dummy data to the second part. Alternatively, the second part can be recorded on another track, in which it is possible to record in different units, e.g. by bit recording in a track that utilizes a DVD recording format. According to the present examples, we can record data of various sizes on the holographic memory effectively while performing large-capacity and high-speed holographic recording.

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Chigasaki, Japan

Junya Iizuka